The primary goal of this research is to identify significant modifiable factors (i.e., diet, lifestyle factors, etc.) and novel risk factors that may predict the risk for GDM and contribute to the prevention of GDM. Within the common theme of insulin resistance and secretion, several important diet and lifestyle associations with GDM have been successfully identified in this effort based on data from the Nurses Health Study II. Several studies on other modifiable risk factors and other novel risk factors are underway based on the Nurses'Health Study and other collaborative studies. In the past year, we have identified several new risk factors including dietary iron inatkes, life course weight characteristics, sugar sweetened beverage consumption, early age for menarche, etc. These papers were presented in the Annual Scientific Meeting of American Diabetes Association, Society for Epidemiologic Research, and Society for Pediatric and Perinatal Research.